EQ7 Series Instruction Manual - TECO-Westinghouse Motor Company

[ 15 ] Inverter overload
Problem Temperature inside inverter has risen abnormally.
Possible Causes
(1) Temperature around the
inverter exceeded the
inverter's specification
range.
(2) Excessive torque boost
specified (F09*)
(3) The specified acceleration/
deceleration time was too
short.
What to Check and Suggested Measures
Measure the temperature around the inverter.
Lower the temperature (e.g., ventilate the panel where the inverter is
mounted).
Check whether decreasing the torque boost (F09*) does not stall the motor.
If no stall occurs, decrease the F09* data.
Recalculate the acceleration/deceleration torque and time needed for the load,
based on the moment of inertia for the load and the acceleration/deceleration
time.
Increase the acceleration/deceleration time (F07, F08, E10 through E15, and
H56).
(4) Overload. Measure the output current.
Reduce the load (e.g., Use the overload early warning (E34) and reduce the
load before the overload protection is activated.). (In winter, the load tends to
increase.).
Decrease the motor sound (Carrier frequency) (F26).
Enable overload prevention control (H70).
(5) Ventilation paths are
blocked.
(6) Cooling fan's airflow volume
decreased due to the
service life expired or failure.
(7) The wires to the motor are
too long, causing a large
leakage current from them.
(8) Running on single-phase
power
[ 16 ] Overspeed
Check if there is sufficient clearance around the inverter.
Change the mounting place to ensure the clearance.
Check if the heat sink is not clogged.
Clean the heat sink.
Check the cumulative run time of the cooling fan. Refer to Chapter 3, Section
3.4.6 "Reading maintenance information – Menu #5 "Maintenance Information"."
Replace the cooling fan.
Visually check that the cooling fan rotates normally.
Replace the cooling fan.
Measure the leakage current.
Insert an output circuit filter (OFL).
Refer to Section 10.7 "If the Inverter is Running on Single-Phase Power," [ 1 ]
and [ 6 ].
Problem The motor rotates in an excessive speed (Motor speed (F03 data) (d32 data, d33 data) 1.2)
Possible Causes
(1) Incorrect setting of function
code data.
(2) Insufficient gain of the speed
controller.
(3) Noises superimposed on the
PG wire.
What to Check and Suggested Measures
Check the motor parameter "Number of poles" (P01*).
Specify the P01* data in accordance with the motor to be used.
Check the maximum frequency setting (F03*).
Specify the F03* data in accordance with the output frequency.
Check the setting of speed limit function (d32 and d33).
Disable the speed limit function (d32 and d33).
Check whether the actual speed overshoots the commanded one in higher
speed operation.
Increase the speed controller gain (d03*.)
(Depending on the situations, reconsider the setting of the filter constant or
the integral time.)
Check whether appropriate noise control measures have been implemented
(e.g., correct grounding and routing of signal wires and main circuit wires).
Implement noise control measures. For details, refer to the EQ7 User's
Manual, "Appendix A."
10-18